Day after day Lakhvir Singh sat in the dock at the Old Bailey, usually with her eyes closed, as family members and her love rival gave evidence against her.
From her arrest - of which a police officer said: "She appeared calm and controlled and did not show emotions" - right up to her conviction, Singh appeared detached from the cruel death she inflicted on a man she professed to love.
The court heard how the 45-year-old mother-of-three had a secret affair with Lakhvinder Cheema, which lasted 16 years.
But two weeks before he was due to be married to Gurjeet Choongh, "lovesick" Singh, laced a pot of curry with Indian aconite, which is known as the "queen of poisons".
Mr Cheema, 39, of Feltham, west London, became engaged to Ms Choongh, 22, in November 2008, after his family began to suspect his taboo affair.
Singh, from Southall, left for India when the engagement was announced, but returned a month later having made up her mind to poison him, the jury heard.
In a desperate 999 call, Mr Cheema said his ex-girlfriend had poisoned him
On Wednesday, she was found guilty of Mr Cheema's murder, but cleared of attempting to murder Miss Choongh.
In the months leading up to the murder, Singh sent texts to Mr Cheema in which she veered between despair - "there is no cure for lovesick persons" - to self-pity - "sometimes I feel you have forgotten me, but my heart says that you cannot forget me".
On 26 January 2009, while Mr Cheema was abroad receiving treatment for cancer, Singh went to his house and put the poison in a container that held the curry.
Her choice of poison was aconite ferox - commonly known as Indian aconite - a herb found in the foothills of the Himalayas that is used in herbal medicines.
Indian aconite comes from a family of aconitum plants, which also grow in Britain, where it is known as monkshood or wolfsbane.
Aconite poison affects the heart and central nervous system, Prof Robin Ferner, a clinical pharmacologist, explained.
"You vomit profusely and it's difficult to stop the vomiting," he said.
"You get abdominal pain and then you get heart trouble and your heart becomes less powerful your heartbeats fade, your heart rhythm is disturbed and that heart rhythm disturbance kills you."
Soon after dinner on the night of the poisoning, the victims began vomiting. The jury heard Mr Cheema's face became numb and within minutes he lost his sight, then the use of his arms and legs.
In a 999 call, the operator asked him if the pair had "food poisoning". He replied: "No not food poisoning, somebody just put poison in our food.
Miss Choongh got engaged to Mr Cheema in November 2008
When asked why would someone poison his food, Mr Cheema said: "My ex-girlfriend, because she was my ex-girlfriend."
Ending the call he told the operator he "can't see properly".
A CCTV camera at his home captured his nephews carrying him and Miss Choongh into a car. As the car starts he can be heard vomiting.
In the hour before his death, he told a doctor Singh had "put something in the food".
One of his tenants, Helen Hurley, said Mr Cheema "looked in a hurry" to change the locks on the evening he was poisoned.
He told her: "I believe my ex-girlfriend was here. I am changing the locks just in case she comes back."
The rapid and fatal effect of the poison alarmed the hospital and police evacuated Mr Cheema's and Singh's homes, suspecting there may have been an airborne or chemical threat.
Officers found a plastic bag containing a brown powder in Singh's coat, which she claimed was medication for a rash on her neck.
But the contents of the powder matched the poison found in the curry - which led to her conviction by the jury.
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